[R] Beginner Question on Persp()

[David Barron]

read.delim creates a data frame (which is a type of list), whereas
persp requires that the z argument be a matrix.  These are different
classes of object in R -- you might want to read the Introduction to R
that ships with the programme.  Try

persp(x,y,as.matrix(z))

On 05/02/07, Tom H. <tom.hatfield at ae.ctscorp.com> wrote:
>
> I recently downloaded R for Windows, running on Win XP.  I'm trying to create
> a perspective plot but not having any luck after reading the R manual and
> several examples found on the Internet.
>
> I have a 100 x 100 matrix of Z data as a tab-delimited text file exported
> from Minitab.  I read this in to R using read.delim; this seemed to go ok.
> I created  X and Y using seq() to get 100 divisions for the X and Y axes.
> Again, everything looked good, when I typed X or Y I got a string of 100
> numbers.
>
> However, when I try to do persp(x,y,z) I get an error something like: (list)
> cannot be coerced to double.  I know the basic data (matrix of z values) is
> ok (no hidden non-numeric values) because Minitab will graph it just fine.
> Any suggestions on how to proceed?  Thanks in advanced for your help.
> --
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>
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-- 
=================================
David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP